WASHINGTON (February 10, 2013)—U.S. Sen. Lindsey Graham, R-S.C., is threatening to hold up Senate confirmation of President Barack Obama's nominees to lead the Defense Department and the CIA until the White House provides more answers about the deadly Sept. 11 attack against a U.S. diplomatic facility in Benghazi, Libya.

Graham says he’s angered by what he calls White House "stonewalling" about the attack that killed four Americans, including the ambassador.

He told CBS he'll hold up Senate action on the nominations of Chuck Hagel as defense secretary and John Brennan as CIA director until he gets what he wants.

Graham said he wants to know what Mr. Obama was doing during the time of the attack and whether he was in touch with Libyan officials.

U.S. Sen. Jack Reed, D-R.I., called Graham's threat "unprecedented and unwarranted."